Four-wheel drive vehicles can be categorized into part-time four wheel drive vehicles that basically operate in a two-wheel drive state and can switch to a four-wheel drive state if necessary, and full-time four wheel drive vehicles that include center differentials disposed between the front wheels and the rear wheels and constantly operate in the four-wheel drive state (for example, refer to Japanese Unexamined Patent Application Publication No. 2000-247159). Four-wheel drive vehicles that include transfer devices having sub-transmission mechanism and operate in both part-time and full-time modes or in multiple different control types (traveling modes) have been put to practical use.
For example, Japanese Unexamined Patent Application Publication No. 2010-149850 discloses a four-wheel drive vehicle that includes a mode selector switch switchable among six traveling modes: a normal mode, a deep snow/muddy road mode, a desert mode, a snow/mud/sand climbing mode, a mogul mode, and a rock mode. The four-wheel drive vehicle operates in a normal traveling mode at start-up of an off-road guidance ECU and then switches to one of the traveling modes selected with the mode selector switch. The driving arrangement (drive mode of the vehicle) recommended for the selected traveling mode is displayed on a guidance screen for presentation of the operating method of the vehicle to a driver. Such presentation can promote the setting of the recommended driving arrangement (position) of the driving system of the vehicle suitable for the selected traveling mode.
The drive modes of a vehicle include a two-wheel drive (2WD) mode, a full-time four-wheel drive (full-time 4WD) mode, a direct-connection four-wheel drive mode in which the sub-transmission mechanism is set to a high gear arrangement (high-direct-connection 4WD mode), and a direct-connection four-wheel drive mode in which the sub-transmission mechanism is set to a low gear arrangement (low-direct-connection 4WD mode). The traveling modes described in Japanese Unexamined Patent Application Publication No. 2010-149850 include the normal traveling mode for normal driving and off-road traveling modes suitable for off-road driving. In general, these drive modes and off-road traveling modes are constantly displayed on a display installed on an instrument panel, for example, so that a driver can also confirm the current modes.
The off-road traveling modes are selected for driving in a rough road, for example, in deep snow, sandy ground, or muddy ground. In general, the traveling modes are selected in the high-direct-connection 4WD mode or the low-direct-connection 4WD mode. A display dedicated to the off-road traveling modes or an area in the display dedicated to the off-road traveling modes is not appropriate in consideration of the frequency of setting the off-road traveling modes and the space and cost required for such display. If the drive modes and the traveling modes are manually selected by a driver, constant display of these modes may be an excess announcement to the driver.